What mistake did I make on my homework please correct it for me

when the chinese communist party took power in 1949, it began to build new di and levees to hold the yellow and yangtze rivers back.

nope native american were.

native pride

the answer would be the third option, "no, ariel should have added 9^2 and 12^2 and compared that to 15^2."

this is found through the pythagorean theorem, which is a^2 + b^2 = c^2.

this is the correct way of solving the problem:

9^2 + 12^2 = 15^2

81 + 144 = 225

225 = 225